This research is a behavioral and pharmacological investigation of the biochemical correlates of behavior. Three principal types of investigations are being carried out: (1) development and analysis of behavioral situations, (2) studies of drug effects on specific behaviors, (3) and studies of specific relations between behavior changes and biochemical or other physiological changes. A systematically related series of discrete trial operant conditioning experiments are being developed for identifying and measuring the specific changes in behavior produced by drugs. Behaviors which are being studies most intensively are learning, memory, and discrimination. Interrelations between drug effects on these different behaviors are of particular interest. At present the behavioral procedures that have been developed are being applied to the analysis of the effects of cholinergic blockers and d-amphetamine in rats; eventually they will also be applied to other classes of drugs. The procedures will also be used for cross-species (pigeons, rats, squirrel monkey) comparisons of drug effects and biochemical correlates, and for study of relationships between behavioral effects and measured tissue levels of injected drugs.